Various dispensers are known and used to dispense fluids such as lotions, soaps and sanitizers, whether as liquid or foam. These dispensers generally include a dispenser housing that is adapted to receive refill units that carry the product that is to be dispensed. The refill units typically include a container, such as a bag or bottle, containing the product, and a pump is associated with the container such that, upon actuation, product is advanced from the container to an outlet of the dispenser. When a refill unit is emptied of product, it is removed, and a new, full refill unit is installed in the dispenser housing. To make efficient use of the volume within the housing, in terms of the amount of product that can be held therein, the container of the refill unit is often sized or contoured to fit intimately within a particular dispenser housing. Similarly, the pump portion of the refill unit is sized to fit within the dispenser housing so as to be operable by actuation mechanisms carried by the dispenser housing. Thus, the refill units are specifically sized and shaped to correspond to certain dispenser housings.
It is desirable to provide refill units that may only be used in a particular, intended dispenser housing. This can be achieved by designing specific dispenser housings that receive specific refill units. For instance, if one desires to place a sanitizer dispenser in a public restroom, a dispenser housing can be designed to have an interior that is specifically shaped to receive only an appropriately-shaped refill unit, and the manufacturers of the dispenser and refill unit can take steps to ensure that appropriately shaped refill units contain only sanitizer. By using such a paired, or associated, dispenser and refill unit arrangement, it can reasonably be assured that the maintenance staff responsible for maintaining the dispenser will only replenish the dispenser with an appropriate refill unit containing an appropriate product.
Keying systems can also be employed to ensure that only refill units of a particular product are installed in a particular intended dispenser housing. In such systems, the dispenser housing is provided with a keying system that is designed to only receive refill units having a corresponding, or complimentary, property recognized by the keying system. For instance, the dispenser housing may include a receiver for receiving a refill unit, wherein the receiver includes a star-shaped keyway. Refill units intended to be used with that particular dispenser housing would then be manufactured to have a star-shaped key positioned so that the star-shaped key fits into the star-shaped keyway when the refill unit is properly installed in the dispenser housing. Certain embodiments of electronic keying systems are also known in the art, such as those described in the jointly owned U.S. Pat. No. 7,028,861 and in the jointly owned U.S. Pat. Pub. No. 2006/0124662.
By employing the above methods, it is possible to reduce the likelihood that a refill unit containing the wrong product will be installed in a given dispenser housing. Unfortunately, some of these methods can be bypassed, and refill units with inappropriate or unintended product can be installed into some of these types of dispensers. Thus, the need exists for a dispenser having a feature to control or limit the operation of the dispenser depending on whether an appropriate refill unit is present in the dispenser housing.